Longcai Tech HCP FS-Series Femtosecond-Optimized Periodically Poled Lithium Niobate (PPLN) Crystal

Overview

The Longcai Tech HCP FS-Series Periodically Poled Lithium Niobate (PPLN) crystal is engineered specifically for ultrafast nonlinear optical frequency conversion in femtosecond laser systems. Based on the quasi-phase-matching (QPM) principle, this PPLN crystal enables highly efficient second-harmonic generation (SHG), sum-frequency generation (SFG), difference-frequency generation (DFG), and optical parametric oscillation (OPO) across a broad mid-infrared to near-infrared spectral range. Its precisely controlled ferroelectric domain grating—fabricated via high-resolution electric-field poling—ensures phase-matching bandwidths compatible with sub-100-fs pulse durations while maintaining high damage threshold and thermal stability. Designed for integration into Ti:sapphire, Yb-fiber, and Er-fiber femtosecond oscillator/amplifier platforms, the FS-Series supports both collinear and non-collinear interaction geometries under low-repetition-rate (1 W) operating conditions.

Key Features

• Femtosecond-optimized domain periodicity: Engineered poling periods ranging from 4.5 µm to 32 µm enable tunable output from 680 nm to >4.5 µm depending on pump wavelength and temperature tuning.
• High-fidelity AR coatings: Broadband anti-reflection coatings applied on both input and output faces minimize group delay dispersion (GDD) and insertion loss—critical for preserving femtosecond pulse integrity.
• Precision thickness control: Standard Z-axis thickness options of 0.5 mm and 1.0 mm balance conversion efficiency, walk-off compensation, and group velocity matching requirements for ultrashort pulses.
• Sub-millimeter length variants: X-dimension options of 0.3 mm, 0.5 mm, and 1.0 mm support compact cavity designs and high-repetition-rate intracavity doubling configurations.
• Low photorefractive sensitivity: MgO-doped LiNbO₃ substrate reduces optical damage accumulation under intense fs illumination, extending operational lifetime in high-peak-power environments.
• Traceable fabrication documentation: Each crystal includes full metrology records—including domain uniformity mapping, surface flatness (λ/10 @ 633 nm), and wavefront distortion (<0.12 λ RMS).

Sample Compatibility & Compliance

The FS-Series PPLN crystals are compatible with standard optomechanical mounts (e.g., Kinematic rotation stages, temperature-controlled ovens) and integrate seamlessly into commercial fs laser platforms including those from Coherent, Spectra-Physics, Light Conversion, and Toptica. All crystals are fabricated in accordance with ISO 9001-certified cleanroom protocols. While not classified as medical or IVD devices, their material composition and processing comply with RoHS Directive 2011/65/EU and REACH Annex XVII restrictions. For regulated R&D environments, traceability data—including batch ID, poling date, and interferometric inspection reports—can be supplied upon request to support GLP-compliant experimental documentation.

Software & Data Management

No embedded firmware or proprietary software is included, as the FS-Series operates as a passive nonlinear optical component. However, Longcai Tech provides downloadable QPM design tools (MATLAB- and Python-compatible) enabling users to calculate optimal poling periods, temperature tuning curves, and acceptance bandwidths for custom pump wavelengths and pulse durations. These tools incorporate Sellmeier coefficients validated against NIST-traceable refractive index measurements and include built-in thermal expansion and thermo-optic coefficient models for LiNbO₃:MgO. Exported simulation outputs are structured in CSV and JSON formats to facilitate integration with LabVIEW, Python-based automation pipelines, and electronic lab notebook (ELN) systems supporting ASTM E2500-17 metadata standards.

Applications

• Ultrafast spectroscopy: Generation of tunable idler beams for time-resolved IR pump-probe experiments.
• Mid-IR frequency comb generation: DFG-based comb extension into the molecular fingerprint region (2–5 µm) for gas sensing and metrology.
• Attosecond science: High-harmonic generation seeding via stabilized few-cycle IR drivers.
• Quantum optics: SPDC-based entangled photon pair sources with controllable spectral correlation width.
• Biomedical imaging: Compact fs-OPO sources for label-free CARS and SRS microscopy systems.
• Industrial metrology: Stabilized fs-SHG references for optical clock distribution and interferometric displacement sensing.

FAQ

What is the maximum peak intensity this crystal can withstand without damage?

Damage threshold is pulse-duration dependent; typical values range from 0.3 GW/cm² (for 100-fs pulses at 1030 nm) to 0.1 GW/cm² (for 30-fs pulses). Exact thresholds are provided per batch in the test report.

Can I specify a custom poling period outside the standard catalog range?

Yes—custom periods from 3.8 µm to 35.0 µm are available with lead times of 6–8 weeks and minimum order quantities of five units.

Is temperature tuning required for phase matching?

Yes—most fs applications require precise oven control (±0.1°C stability) over the range of 25–200°C to maintain phase matching; recommended controllers are listed in the integration guide.

Do you provide mounting hardware or temperature-stabilized ovens?

Mounting adapters and OEM-compatible oven modules are available as optional accessories; contact technical sales for mechanical drawings and interface specifications.

How is crystal orientation verified prior to shipment?

Each unit undergoes X-ray diffraction (XRD) rocking curve analysis to confirm orientation within ±0.2°, with results documented in the certificate of conformance.